The metadata below describe the original scanning. Follow the "All Files: HTTP" link in the "View the book" box to the left to find XML files that contain more metadata about the original images and the derived formats (OCR results, PDF etc.). See also the What is the directory structure for the texts? FAQ for information about file content and naming conventions.
"To Mr. Dan has fallen the task of seeking for and photographing most of the examples. Mr. Willmott having undertaken the writing of the descriptive notes, and the preparation of the illustrations to chapter III."--Pref